Metal and wood composite framing member

ABSTRACT

A manufactured wood and metal joist consisting of three individual pieces fabricated together to make a single joist. The overall length of the joist consists of a solid wood end of a determined length shrouded by a hollow metal shape of a determined length. Another solid wood piece of determined length is at the opposite end also shrouded by the hollow metal shape.

[0001] This application claims priority based on U.S. Provisional Patent Application Serial Nos. 60/262,625 and 60/219,262.

FIELD OF THE INVENTION

[0002] This invention relates to the residential and light commercial construction industries which can utilize a composite framing joist with the hollow metal portion used for the long spanning capabilities and the solid wood ends used for the trimming and nailing capabilities.

BACKGROUND OF THE INVENTION

[0003] The spanning capabilities of a solid wood joist cannot compare to the spanning capabilities of the composite joist when both joists are of the same size dimensionally. The hollow metal section is far stronger and stiffer than a solid wood section. The construction industry does not have a metal joist product that can be trimmed to length with a standard wood cutting circular saw, and then nailed into place with a pneumatic or a standard hammer, as typically used in the residential and light commercial construction industries. This composite joist offers the architect, builder and owner, another option when designing homes and other buildings with large floor and roof spans. The composite joist can be manufactured to standard lengths and delivered to the lumber yard or job site just as typical framing lumber is made available to the public.

[0004] The residential building industry commonly uses wood members as the primary framing material of choice. Where as the commercial building industry commonly uses steel members as the primary framing material of choice. These framing members are typically installed at a common spacing of 16″ or 24″ on centers. While both wood and steel members have a proven record of their own, combining these two materials in a new joist configuration uses the best attributes of both materials. The central section of the joist is manufactured using a common gage steel thickness and formed into a rectangular shape. This steel portion of the joist is used for the long spanning characteristics and high strength to weight ratio. The steel portion of the joist is also dimensionally more stable when compared to wood members of similarly long spans. At the two ends of the composite joist are solid wood members, rectangular in shape and shrouded by the hollow steel section. These wood ends protrude past the steel section a determined distance. The wood portion is rigidly attached to the steel portion of the joist, to allow for the bending forces and shear forces to be continued along the length of the joist and to the very ends. The protruded wood ends can them be cut to the required length at the job site and then nailed into place using typical wood framing tools as used in residential construction. These wood ends eliminate the need for using metal framing tools at the job site, such as special saws, crew guns and self-tapping fasteners, but still allows incorporating the strength and safety of steel joists into the home or building project.

BRIEF SUMMARY OF THE INVENTION

[0005] Both materials, steel and wood have their advantages and disadvantages when used as framing members. Steel is strong and straight, whereas wood is not as strong and will warp and twist during its lifetime. Steel is time consuming to cut and connect together, whereas wood is quicker to cut and fasten together. This composite joist is to be used as a floor or roof framing member which is typically spaced 16″ or 24″ on center, and up to 48″ on center, having a sheathing material applied to the top surface. A sheathing material, such as drywall (sheetrock) can also be applied to the bottom surface of the joist if required. The object of the invention is to provide a long spanning, light gage steel joist with trimable wood ends free of any steel interference during the cutting or nailing process.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The figures which illustrate the embodiments of the invention are:

[0007]FIG. 1 is a perspective view of the composite joist invention;

[0008]FIG. 2 is a side view of the joist of this invention;

[0009]FIG. 3 is a cross sectional view taken along line 3-3 of FIG. 2;

[0010]FIG. 4 is a cross sectional view taken along line 4-4 of FIG. 2;

[0011]FIG. 5 is a cross sectional view taken along line 5-5 of FIG. 2;

DETAILED DESCRIPTION OF THE INVENTION

[0012] The features of this invention are described in the following drawings.

[0013]FIG. 1 generally illustrates the composite joist 10 in a perspective view looking down on the joist. This joist drawing illustrates that the wood ends can be cut to the required length without the interference of the metal portion of the joist, and then nailed into a supporting wood component such as 16. The joist is designed to support long floor, roof or ceiling spans, and the associated live and dead loads. Each joist 10 is spaced at intervals of usually 16″ or 24″ on center and up to 48″ on center to provide a framing assembly for a floor, roof, or ceiling. These joists can be manufactured to any length, any depth, and using any gage metal thickness.

[0014]FIG. 2 illustrates the side elevation of the composite joist and indicates the locations of section cuts 3-3, 4-4, and 5-5 along the length of the joist. Each composite joist is placed in the horizontal position as with a floor, or near horizontal position as in the case of roof or ceiling framing assembly, and support the required live and dead loads of the building. Each composite joist consists of a middle component 20. This middle component 20, is the light gage, rectangular shaped, hollow section, which is the longest portion of the joist. The ends of joist are the wood components 24 and 26. These ends are of a solid wood material and in a rectangular shape which can be cut, trimmed and nailed into place without the interference or encumbrance of the metal component 20.

[0015]FIG. 3 illustrates the section cut at location 3-3 on FIG. 2. This metal section of the joist is manufactured by using a flat sheet of steel, and bending it into the required shape and dimensions. This metal component 20, can be of any dimensional size and any gage required. The metal sheet is formed into a rectangular shape, with the edges nested together 20, to form a right bond. Along the length of the metal component 20, are cut-out holes for plumbing or electrical lines to pass safely through. These cut-outs are of a required size and shape and at regular intervals. The metal material can be painted or galvanized to protect the steel from a corrosive environment.

[0016]FIG. 4 illustrates the section cut at location 4-4 on FIG. 2. This section is the area where the hollow metal section interfaces, and is attached and to the solid wood section. The attachment of the two components is made by either nailing, gluing, banding, or a combination of the these methods or more depending on the joist loading requirement. The metal piece 20 is formed, the wood ends 24 and 26 are inserted into 20, and these parts are fixed together to form a rigid joist.

[0017]FIG. 5 illustrates the section cut at location 5-5 on FIG. 2. This section is the solid wood or nailable material that makes up the ends of the joist. These wood (or nailable material) pieces are the same rectangular shape, and sized to fit into the end of the metal piece 20. This piece, 20 or 26 can be cut or trimmed anywhere where the wood is exposed beyond the end of the metal piece 20, by using a standard wood cutting saw. Once the joist is cut to the required length, the joist can then be nailed or fastened into place as shown in FIG. 1.

[0018] Of course, there are many advantages of using steel joists in construction. The strength of steel, the straightness of steel, and the uniformity of steel all are good examples for using steel. This composite joist, uses the benefits of steel and the benefits of wood, to provide an alternative product to the construction industry. 

What is claimed is:
 1. A composite joist/stud comprising a metal middle section having opposite ends, and two end sections secured to said opposite ends, respectively, to form said joist or stud, said end sections being of a nailable material.
 2. The joist or stud of claim 1 wherein said middle section is of sheet metal folded longitudinally to form a hollow section having a rectangular cross-section between said opposite ends.
 3. The composite joist or stud of claim 2 wherein the cross-section is uniform between the ends.
 4. The composite joist or stud of claim 1 wherein said end sections telescope into said hollow middle section and secured therein.
 5. The composite joist or stud of claim 4 wherein said two end sections are secured to said middle section by at least one of the group of securance methods consisting of adhesive, nails, crimped sections, press plate, banding, or combinations thereof.
 6. The composite joist or stud of claim 2 wherein the longitudinal edges of said middle section are nested and crimped together.
 7. The composite joist or stud of claim 2 wherein the longitudinal distal edges of said sheet of said middle section are nested and crimped together at a position to provide additional tensile strength where most of the tensile strength is to be applied.
 8. The composite joist or stud of claim 1 wherein said nailable material is wood.
 9. The composite joist or stud of claim 1 is of the group of joist and studs consisting of floor joist, roof joist, ceiling joist and wall studs.
 10. The composite joist or stud of claim 9 wherein said joist or stud has overall dimensions generally the same as conventional 2×4, 2×6, 2×8, 2×10, 2×12, 3×14, and larger dimensional lumber with lengths commensurate to required loads.
 11. The composite joist or stud of claim 1 further comprising spaced apart cutouts along the length of joist or stud for running wire or other construction trade mechanicals through the joist when desired.
 12. The composite joist or stud of claim 1 wherein said end sections are treated for moisture protection.
 13. The composite joist or stud of claim 1 wherein said end sections are treated for fire protection.
 14. The composite joist or stud of claim 1 wherein said middle section is comprised of sheet metal folded longitudinally to form a hollow generally rectangular in cross-section, said middle section having a uniform cross-section, said middle section being galvanized or painted or otherwise protected from a corrosive atmosphere.
 15. The composite joist or stud of claim 2 wherein said sheet is sheet steel.
 16. The composite joist or stud of claim 2 wherein said sheet material is galvanizes sheet steel or painted sheet steel.
 17. The composite joist or stud of claim 4 wherein the joinder between said middle section and said two end sections have a tensile strength greater than the tensile strength of said middle section.
 18. The composite joist or stud of claim 1 wherein said middle section is more resistant to twisting forces about its longitudinal axis than conventional beams of cross-sections having a generally “C” shape or “Z” shape.
 19. The composite joist or stud of claim 15 wherein said sheet material of said middle section is cold rolled steel.
 20. The composite joist or stud of claim 20 wherein said cold rolled steel is from about 14 gage to about 24 gage in thickness.
 21. The composite joist or stud of claim 8 wherein the wood is chosen from the group of woods comprising pine and hen-fir.
 22. The composite joist or stud of claim 8 wherein each of said end sections are two feet long.
 23. The composite joist or stud of claim 10 wherein the length of said stud or joist is from about 8 feet to about 30 feet in two foot increments.
 24. The composite joist or stud of claim 19 wherein said C-shaped elements are welded together.
 25. The composite joist or stud of claim 6 wherein said distal edges are welded together.
 26. A composite joist/stud comprising a metal middle section having opposite ends, and two end sections secured to said opposite ends, respectively, to form said joist or stud, said end sections being of a nailable material, said middle section is of sheet metal folded longitudinally to form a hollow section having a rectangular cross-section between said opposite ends, said cross-section is uniform between the ends, said end sections telescope into said hollow middle section and secured therein, said two end sections are secured to said middle section by at least one of the group of securance methods consisting of adhesive, nails, crimped sections, press plate, banding, or combinations thereof, the longitudinal edges of said middle section are nested and crimped together, said joist or stud has overall dimensions generally the same as conventional 2×4, 2×6, 2×8, 2×10, 2×12, 3×14, and larger dimensional lumber with lengths commensurate to required loads, the joinder between said middle section and said two end sections have a tensile strength greater than the tensile strength of said middle section, said middle section is more resistant to twisting forces about its longitudinal axis than conventional beams of cross-sections having a generally “C” shape or “Z” shape, the length of said stud or joist is from about 8 feet to about 30 feet in two foot increments, said distal edges are welded together. 